This is a renewal application for a multi-disciplinary hematology training program at the New York University School of Medicine. The program is designed to provide two-year research opportunities for 5 post-doctoral fellows under the guidance of a faculty of 13 mentors. The formal teaching activities include a core curriculum hematology course, weekly seminars and the availability of courses in molecular biology, immunology and statistics. The training faculty consists of academic hematologists with active laboratories applying basic science methods to the study of hematologic disorders as well as mentors of the basic science departments of NYU Medical Center. The training faculty consists of academic hematologists with active laboratories applying basic science methods to the study of hematologic disorders as well as mentors of the basic science departments of NYU Medical Center. There is abundant interaction among the faculty members within the program as well as with other scientists at this institution and elsewhere. The clinical research at this institution has been recognized by the NIH and its designation as a Comprehensive Cancer Center and an AIDS Center. The program director's research spans both areas. New faculty members have strengthened the basic science orientation of the program. The faculty works within this framework to train physician-scientists for future work in the academic community. The proposed research areas span basic science (cell proliferation, signal transduction, homeobox genes) in the laboratories of Drs Schlessinger, Basilico, Ziff and Takeshita, to direct clinical relevance (angiogenesis, hematopoiesis, thrombopoiesis, retinoic acid receptors, antigen-immuno regulation, lymphomas, chronic lymphocytic leukemia, Kaposi's sarcoma, amyloidosis, thrombosis in the newborn and thrombosis in cancer) in the laboratories of Drs. Green, Basch, Zucker-Franklin, Takeshita, Thorbecke, Inghirami, Jacobson, Huang, M. Karpatkin and S. Karpatkin. A current theme of all the projects is their orientation to human disease. These aims will be accomplished by training promising candidates in the design. execution and evaluation of experiments yielding results that will be offered to peer-reviewed journals. Eventually, the trainees will take their place in future ranks of academic medicine using the approached learned during their stay with our faculty.